1. Technical Field
The present invention relates to an amphibious vehicle and, more particularly, to a land vehicle having retractable water flotation hulls and rear-mounted propulsion means.
2. Background Art
There is a need for vehicles that can travel on land and on water and this need exists for recreational use as well as for commercial and military uses. People frequently travel and go to different or unique places, some accessible by car via road and some inaccessible by road, but perhaps accessible by boat via water. Many times, even places accessible by road would be more accessible by boat, or vice versa. Having separate vehicles, such as a car towing a trailered boat, requires that the boat be detrailered and launched into the water and that supplies, such as food, clothes, and other necessities, be transferred from the car to the boat and then back again when returning to the car.
In addition, the car must be left in a parking lot or at the side of the road or arrangements made to have the car transferred by a third party to the destination. Often, parking is inconvenient or expensive. Sometimes, there are limits on space where the vehicles are switched. For example, there may be no room to launch boats or the road may restricted to vehicles without trailers. At other times, when one does not plan to use a boat, it is still needed and may be parked somewhere else. In all these cases, amphibious vehicles would be advantageous.
There have been many attempts in the past to construct vehicles that are amphibious. These include cars that convert to boats, boats that convert to cars, trailers that convert to houseboats, and the like. The types of conversions include cars with wheels that can be folded away or retracted, vehicles with stowable pontoons that can moved into operative position, boats with extendible wheels, and the like.
Self-propelled vehicles are known in the prior art. Kovac U.S. Pat. Nos. 4,691,657 and 4,802,433 show an amphibious vehicle with watertight pontoons movable between a stowed position atop the vehicle and an operational position along each side of the vehicle by pivot arms driven by hydraulic cylinders located within the vehicle.
Abel U.S. Pat. No. 5,315,950 shows an amphibious recreational vehicle, which carries an auxiliary vehicle, provided with top-stored buoyancy tanks swung into lowered position by a combination of pivot arms connected to winch-driven cables and piston-cylinder devices. Separate propulsion units stored internally are lowered from the vehicle bottom to provide water propulsion. The propulsion units have wheels so the vehicle can be moved along the ground towards water.
An example of a trailer having pontoons stowable on the roof of the cabin is found in Gail U.S. Pat. No. 4,048,685. The pontoons are lowered and the cabin raised from a launch position to a water position by means of cable-operated pivot arms that have lockable rollers that are movable within a vertical track. A folding deck can be deployed on and between the pontoons.
Stowing pontoons on top of a wheeled boat is generally shown in Levinson U.S. Pat. No. 3,134,991 where pontoons are manually placed and in Livingstone U.S. Pat. No. 3,172,134 where pontoons are pivotally mounted and moved by a cable mechanism.
Davis U.S. Pat. No. 6,971,931 discloses an amphibious vehicle having a mono hull with a propeller drive, road wheels fore and aft on each side of the hull pivotally mounted for vertical movement between deployed and stowed positions, and a pair of sponsons pivotally connected for lateral movement between stowed and deployed positions outward from the hull.
A similar type vehicle is shown in Redman U.S. Pat. No. 6,526,900, wherein a wheeled-boat has vertically retractable wheels and a pair of inflatable lateral pontoons.
Engler U.S. Pat. No. 5,687,669 shows an amphibious vehicle having a pair of pontoons stowed beneath the vehicle and pivotable to a deployed position alongside the vehicle. The road wheels are carried by the pontoons and are disengaged from the road and stowed above the water line when the pontoons are being used. Jet drives are mounted in the pontoons.
Messano U.S. Pat. No. 6,840,825, which shows a similar construction, contemplates pivoting side hulls with wheels for use with motorhomes, trailers, SUVs and the like.
Veazy U.S. Pat. No. 3,933,112 discloses a mini-bus or van comprising an amphibious vehicle having a pair of removable thin pontoons that are manually attachable to the sides thereof by tubular brackets. The vehicle includes a bow attachment, a stern attachment, and a boat that is stored upside-down over the vehicle's open top to act as a roof.
Wheeled boats with foldout pontoons, decks or cabins are shown in White U.S. Pat. No. 2,727,484 for a house trailer, Allen U.S. Pat. No. 3,673,622 for a trailer camper, Kelley U.S. Pat. No. 3,877,094 for a combination trailer and pontoon boat, Bergeron U.S. Pat. No. 4,981,100 for a trailer and boat assembly with lateral pontoons pivotable into the cabin interior, and Chacon U.S. Pat. No. 6,640,737 for an expanding catamaran boat.
While all of the prior art devices are sufficient for their intended function, other constructions may provide features that may be more desirable to a user.